The zerg of StarCraft II have finally appeared, attacking terran forces. So far only the zergling, baneling and the "new" overlord have appeared. Source: StarCraft Legacy.

21th November 2007 - The Story So Far

Blizzard Entertainment has posted a slightly different version of the events of StarCraft Episodes I-III (and a bit before). There seems to be a few retcons, which had been previously mentioned in novels (eg. the ranks of Edmund Duke and Artanis). Source: The Story so Far... Part 1: StarCraft.